This invention relates to envelopers for web winding machines, and more particularly to an enveloper assembly which is arranged to accomplish core envelopment in either of two winding directions.
The automatic partial wrapping of a core by a web, in an automatic roll changer apparatus, has been known for many years. The patent of Kohler et al, U.S. Pat. No. 2,586,833 issued Feb. 26, 1952 discloses enveloper apparatus in combination with a roll changing winder to provide for the continuous operation by means of which a continuously moving web of material, such as paper, plastic, or the like, may be transferred from a completed roll to a new core, so that successive rolls of web may be formed without interrupting the winding operation. A later improved form of enveloper is shown in Marczincsin, U.S. Pat. No. 2,787,427 issued Apr. 2, 1957, in which a web was caused to wrap considerably more than one-half of the circumference of the core, and the apparatus included a cutting knife in which the transfer of the web was affected by a knife which moved in the space between the core and a guiding member, in the direction of rotation of the core, so that the web was severed in this space and the resulting leading end of the web was started on the new core. A still more recent version of an enveloper is shown in Penrod, U.S. Pat. No. 3,478,975 issued Nov. 18, 1969, in which the enveloper is shown in combination with a turret winder.
In the various arrangements shown in the above-identified patents, the enveloper was capable of wrapping the web about the core in one direction of rotation only. In those instances where the core was to be operated in opposite direction, so that the other side of the web was turned out in winding, it was necessary to employ an auxiliary or second core enveloper assembly for that purpose. This resulted in a highly cluttered area at the roll change station, and provided apparatus which was difficult to access, thread, and maintain.